The FTSE-100 firm said it was benefitting from people switching to cheaper alternatives including own label goods, an area where B&M has performed well over the last few years.

"We are actively responding to the short-term pressure on consumers from the cost-of-living crisis, with a relentless focus on price and value," CEO Alejandro Russo said in a statement.

Shoppers have been buying more own label lines, which are usually cheaper than branded products, as they grapple with soaring food and energy bills, helping discount retailers outperform their mainstream peers.

"With inflation still biting hard, shoppers are desperately searching for ways to save money wherever they can and B&M is benefitting from this focus on frugality," said Hargreaves analyst Susannah Streeter.

Sales of own-label products at British supermarkets have grown at double the speed of branded goods in 2023, data from market researchers NIQ showed on Wednesday.

B&M, which sells everything from toys to frozen food and garden furniture, reported adjusted core profit of 573 million pounds ($710 million) for the year ended March 25, down 7.4% from the year before.

The company had expected adjusted earnings before interest, taxes, depreciation, and amortization of 560-580 million pounds.

Its shares were up 6% at 501 pence at 0808 GMT, the biggest gain on London's blue-chip index.

B&M's sales, which had got a boost from COVID-induced demand for essential items, continued to perform better than pre-pandemic times.

Its annual margin, however, fell to 11.5% from 13.2% the year before, hit by a first-half downturn in its UK store sales.

Like-for-like sales for its UK unit in the first nine weeks of the new financial year were up 8.3%.

($1 = 0.8070 pounds)

(Reporting by Prerna Bedi and Yadarisa Shabong in Bengaluru; Editing by Shailesh Kuber and Mark Potter)

By Prerna Bedi and Yadarisa Shabong